Tyler Hamilton, speaking to the CBS programme 60 Minutes, described an alleged systematic programme of doping in the US Postal team in which he claimed Armstrong played a leading role. Among his claims, Hamilton implicated the UCI by alleging Armstrong tested positive at the 2001 Tour de Suisse. He said Armstrong, who has always denied using drugs, made a deal with the UCI, and the body "figured out a way for it to go away".

However, the UCI condemned Hamilton and dismissed his claims. "The International Cycling Union categorically rejects the allegations made by Mr Tyler Hamilton, who claims that Lance Armstrong tested positive for EPO during the 2001 Tour of Switzerland and had the results covered up after one of his representatives approached the Lausanne laboratory responsible for analysing test results from the event," the UCI said.

"The UCI is deeply shocked by the seriousness of the allegations made on the 60 Minutes programme aired by US television network CBS, and by the extent of the media interest in the case, and wishes to state once again that it has never altered or hidden the results of a positive test.

"The allegations of Mr Tyler Hamilton are completely unfounded. The UCI can only express its indignation at this latest attempt to damage the image of cycling by a cyclist who has not hesitated to abuse the trust of all followers of cycling on several occasions in the past.

"At no time did he see fit to inform the UCI of the events he claims to have witnessed 10 years ago, and which he is now using in his attempt to harm the UCI. The UCI can only confirm that Lance Armstrong has never been notified of a positive test result by any anti-doping laboratory."

The UCI said no such deal would be feasible under its regulations and hinted at action being taken against Hamilton. "Aside from the fact that no legal action may now be taken in respect of events that occurred in 2001, the UCI also wishes to point out that in doping cases it must abide by the rules of evidence; any statutory or scientific evaluation must necessarily be made on the basis of the rules, knowledge and detection methods available at the time.

"Once again, the UCI wishes to state that no manipulation or cover-up has occurred in respect of its anti-doping procedures. The UCI will continue to defend its honour and credibility by all means available, and reserves the right to take any measures it deems necessary against Mr Hamilton or any other person.

"The UCI confidently awaits the results of the inquiry being conducted by the US justice system. It hopes that the investigations may be concluded swiftly and the truth ascertained, so that the sport of cycling may be spared further unnecessary damage."

During his interview with 60 Minutes, portions of which were aired on Thursday and Friday, Hamilton said he had seen Armstrong take the blood-booster EPO and testosterone as well as having a blood transfusion. Hamilton, a team-mate of Armstrong's between 1998 and 2001, admitted he had taken EPO "many, many times" and alleged that drug use was rife throughout the sport.

The CBS programme is claiming another ex-US Postal rider, George Hincapie, has told a federal investigation both he and Armstrong used banned substances although Hincapie had already moved to distance himself from the reports before the weekend.

The former Olympic champion Hamilton, who retired in 2009 after receiving an eight-year ban for a second doping offence, has also testified to a grand jury behind closed doors about doping at US Postal.

Of Armstrong, Hamilton said: "He obviously was the biggest rider in the team and he helped to call the shots. He doped himself like everybody else, but he was just being part of the culture of the sport. He was the leader of the team and he expected for going in, for example, the '99 Tour [that] we were going to do everything possible to help Lance win. We had one objective, that's it."

Armstrong hit back when Hamilton's claims were first aired by CBS and his spokesman Mark Fabiani released a statement on www.facts4lance.com which said: "We have already responded in great detail at www.facts4lance.com. Throughout this entire process CBS has demonstrated a serious lack of journalistic fairness and has elevated sensationalism over responsibility.

"CBS chose to rely on dubious sources while completely ignoring Lance's nearly 500 clean tests and the hundreds of former team-mates and competitors who would have spoken about his work ethic and talent."

There was also support for Hincapie, always a close associate of Armstrong. "In its unpardonable zeal to smear Lance Armstrong, CBS has also attacked the reputation of George Hincapie," the statement said. "We are confident that the statements attributed to Hincapie are inaccurate and that the reports of his testimony are unreliable."